1. Field of the Invention
This invention relates generally to a hunting arrow and, more particularly, to a system for tracking a hunting arrow and/or a game animal shot thereby, by means of radio signals emanating therefrom.
2. Description of the Prior Art
In the hunting of animal game with a bow and arrows, it is often difficult to locate a hunting arrow after it is shot from the bow. This may be either because it has missed the target and landed in an area of dense foliage or the like, or has become embedded in the target animal without killing it, the animal then fleeing the area. In order to assist in locating such hunting arrows there have been provided radio locating systems, whereby a radio transmitter carried by the arrow emits signals which can be detected by a directional receiver carried by the hunter.
Some such prior systems have utilized specially-designed customized arrows with built-in transmitters and/or antennas therefor, such customized arrows being disclosed, for example, in U.S. Pat. Nos. 4,704,612 and 3,790,948. Such tracking systems are expensive, since they require the hunter to purchase the specialized custom arrows.
U.S. Pat. No. 4,704,612 also discloses the concept of utilizing the metal shaft of an arrow as a transmitter antenna, but this requires the use of metal arrows.
U.S. Pat. No. 4,885,800 discloses a transmitter which is removably mountable on a standard arrow, but makes no provision for a transmitter antenna.
Of necessity, the batteries used to power an arrow-mounted transmitter must be very small, thereby inherently limiting the amount of power available, and restricting battery life. It is known to provide inertia-activated means for connecting the battery to the transmitter only in response to impact of the arrow, so that the transmitter is not operated until it is needed. But such systems have utilized switch means for mechanically connecting and disconnecting the battery from the transmitter, with attendant reliability problems.
U.S. Pat. No. 4,704,612 also discloses the use of a pulsed transmitter output signal, which further serves to reduce battery consumption. However, prior systems have not effectively tailored the output signal of the transmitter to minimize power consumption, while at the same time maximizing the strength of the transmitted signals to insure an adequate reception range.